The present invention relates generally to on-board vehicle systems and, more particularly, to a system and method for determining which state a vehicle is presently in and for monitoring, recording and reporting the mileage driven by a vehicle in a particular state.
With the advent of vehicle fleet management and monitoring systems, elaborate computerized communication systems directed at automatically obtaining and recording vehicle location and a wide variety of other information as a vehicle covers its route, numerous on-board computer systems have evolved. The information collected by these systems can be used for a myriad of purposes which encompass automated customer billing systems, computerized dispatching, trip reporting and other such tasks. One type of information available from an on-board vehicle computer is the present location of the vehicle in terms of its geographic latitude and longitude coordinates. One particularly prevalent way of obtaining this data is through a global positioning system (GPS) receiver which captures positional information from signals transmitted over satellite.
However, oftentimes it is necessary to convert the raw coordinate data into a more useful form which provides additional information such as what state, city, province, county or other defined geographical territory the vehicle is traveling in. This information is particularly useful in various fleet and trucking applications such as in performing automated road use tax calculations as well as various trip reporting functions. However, even when coordinate data for the boundary lines of various geographic entities has been pre-stored in memory, the process of individually comparing the current location coordinates to boundary coordinate data for each entity, in order to determine whether the current point lies within that boundary, can become quite computer intensive.
The vehicle state mileage determination system of the present invention includes an on-board processor having stored in memory thereof ordered coordinate data points defining the boundary line of each of a set of geographic entities. Associated with each entity is an additional ordered set of data points which can be joined to form an imaginary polygon which substantially encloses the entity's border.
Each vehicle location coordinate data point acquired by the vehicle position determining system is compared with the boundary line data associated with the last entity the vehicle was determined to be traveling in. If the vehicle location point is determined to fall within that entity's boundary, an OBC memory location for accumulating the mileage traveled by the vehicle with that entity is updated with the distance traveled by the vehicle since the last mileage calculation update. If, however, the new location point does not fall within the entity boundary, the point is then compared to the polygon-forming points associated with certain other entities.
For an imaginary polygon having the new vehicle location point falling therewithin, the point is then compared to the associated entity boundary to confirm whether or not the location point falls within the subject entity border. If it does not, additional entities are checked until an entity location can be positively confirmed. As each entity location is confirmed, the incremental mileage traveled by the vehicle since the last update is added to a value stored in OBC memory representing the cumulative mileage traveled by the vehicle within that entity.
The present system and method thus provide a more convenient and faster way to determine the state, or other such geographic entity, in which a vehicle is located given its latitude and longitude coordinates. The data is continually updated and stored, enabling the creation of an automated database which requires no manual interaction. Data processing and storage are kept to a minimum to make this system effective in an on-board application.
These and other features and advantages of the present invention will become apparent upon review of the following description taken in conjunction with the accompanying drawings.